U.S. patent number 9,902,238 [Application Number 15/272,625] was granted by the patent office on 2018-02-27 for articles including anticondensation coatings and/or methods of making the same.
This patent grant is currently assigned to Guardian Glass, LLC. The grantee listed for this patent is Guardian Glass, LLC. Invention is credited to Jean-Marc Lemmer, Nestor P. Murphy.
United States Patent |
9,902,238 |
Lemmer , et al. |
February 27, 2018 |
Articles including anticondensation coatings and/or methods of
making the same
Abstract
Certain example embodiments of this invention relate to articles
including anticondensation coatings that are exposed to an external
environment, and/or methods of making the same. In certain example
embodiments, the anticondensation coatings may be survivable in an
outside environment. The coatings also may have a sufficiently low
sheet resistance and hemispherical emissivity such that the glass
surface is more likely to retain heat from the interior area,
thereby reducing (and sometimes completely eliminating) the
presence condensation thereon. The articles of certain example
embodiments may be, for example, skylights, vehicle windows or
windshields, IG units, VIG units, refrigerator/freezer doors,
and/or the like.
Inventors: |
Lemmer; Jean-Marc
(Wincheringen, DE), Murphy; Nestor P. (West
Bloomfield, MI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Guardian Glass, LLC |
Auburn Hills |
MI |
US |
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Assignee: |
Guardian Glass, LLC (Auburn
Hills, MI)
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Family
ID: |
44504931 |
Appl.
No.: |
15/272,625 |
Filed: |
September 22, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170015178 A1 |
Jan 19, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14625888 |
Feb 19, 2015 |
9469767 |
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13870107 |
Mar 17, 2015 |
8980386 |
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13647576 |
May 21, 2013 |
8445083 |
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12662894 |
Nov 6, 2012 |
8304045 |
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12659196 |
Oct 23, 2012 |
8293344 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C
14/0652 (20130101); C23C 14/081 (20130101); E06B
3/6715 (20130101); C23C 14/083 (20130101); C23C
14/34 (20130101); B60J 1/002 (20130101); C23C
28/04 (20130101); C03C 17/3435 (20130101); C09D
5/00 (20130101); C23C 14/086 (20130101); C03C
17/3417 (20130101); C03C 2217/22 (20130101); Y10T
428/2495 (20150115); C03C 2218/154 (20130101); C03C
2217/281 (20130101); C03C 2217/214 (20130101); C03C
2217/231 (20130101) |
Current International
Class: |
B32B
15/04 (20060101); C23C 28/04 (20060101); C23C
14/08 (20060101); C23C 14/34 (20060101); C23C
14/06 (20060101); C09D 5/00 (20060101); E06B
3/67 (20060101); C03C 17/34 (20060101); B60J
1/00 (20060101); B32B 17/06 (20060101) |
Field of
Search: |
;428/426,428,434,688,689,699,701,702 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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10 2008 028 141 |
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Dec 2009 |
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DE |
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1 043 606 |
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Oct 2000 |
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EP |
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2 031 756 |
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Apr 1980 |
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GB |
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2 127 231 |
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Oct 1999 |
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RU |
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2 179 537 |
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Feb 2002 |
|
RU |
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WO 95/13189 |
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May 1995 |
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WO |
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WO 01/55752 |
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Aug 2001 |
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WO |
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WO 2009/149889 |
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Dec 2009 |
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WO |
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Other References
US. Appl. No. 14/625,888, filed Feb. 19, 2015; Lemmer et al. cited
by applicant .
U.S. Appl. No. 13/870,107, filed Apr. 25, 2013; Lemmer et al. cited
by applicant .
"Homogeneously Aligned Liquid Crystal Display on Silicon Oxynitride
Thin Film Using Ion Beam Bombardment"; Oh et al., Materials
Chemistry and Physics 117 (2009) pp. 355-358. cited by applicant
.
"A Full Description of a Simple and Scalable Fabrication Process
for Electrowetting Displays", Zhou et al., Journal of
Micromechanics and Microengineering 19, (2009) pp. 1-12. cited by
applicant .
U.S. Appl. No. 12/320,664, filed Jun. 4, 2009; Veerasamy. cited by
applicant .
U.S. Appl. No. 13/647,576, filed Oct. 9, 2012; Lemmer et al. cited
by applicant .
U.S. Appl. No. 12/385,802, filed Aug. 20, 2009; Lu et al. cited by
applicant .
U.S. Appl. No. 12/461,792, filed Dec. 31, 2009; Blacker et al.
cited by applicant .
U.S. Appl. No. 12/591,611, filed Nov. 25, 2009; Veerasamy. cited by
applicant .
U.S. Appl. No. 12/654,594, filed Dec. 23, 2009; Blacker. cited by
applicant .
U.S. Appl. No. 12/385,234, filed Aug. 8, 2009; Lemmer. cited by
applicant .
Russian Office Action for Application No. 2012141044 dated Nov. 16,
2016. cited by applicant .
EP Office Action for Application No. 11 797 073.1. cited by
applicant.
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Primary Examiner: Colgan; Lauren R
Attorney, Agent or Firm: Nixon & Vanderhye P.C.
Parent Case Text
This application is a continuation of Ser. No. 14/625,888, filed
Feb. 19, 2015 (U.S. Pat. No. 9,469,767), which is a continuation of
Ser. No. 13/870,107, filed Apr. 25, 2013 (now U.S. Pat. No.
8,980,386), which is a continuation of Ser. No. 13/647,576, filed
Oct. 9, 2012 (now U.S. Pat. No. 8,445,083), which is a continuation
of Ser. No. 12/662,894, filed May 10, 2010 (now U.S. Pat. No.
8,304,045), which is a continuation-in-part (CIP) of U.S. Ser. No.
12/659,196, filed Feb. 26, 2010 (now U.S. Pat. No. 8,293,344), the
disclosures of which are all hereby incorporated herein by
reference.
Claims
What is claimed is:
1. A vehicle windshield comprising: first and second glass
substrates of the vehicle windshield; wherein the first and second
glass substrates of the vehicle windshield are coupled together; a
coating comprising a plurality of thin film layers provided on the
first glass substrate, the plurality of thin film layers including,
in order moving away from the first glass substrate: (a) a first
dielectric layer comprising silicon nitride; (b) a second
dielectric layer comprising silicon oxynitride; (c) a layer
comprising indium-tin-oxide (ITO) 75-175 nm thick, (d) a third
dielectric layer comprising silicon nitride, and wherein the third
dielectric layer comprising silicon nitride is located over and
directly contacting the layer comprising indium-tin-oxide so that
the layer comprising indium-tin-oxide is located between at least
the first glass substrate and the third dielectric layer; and (e) a
layer comprising aluminum oxide, wherein the layer comprising
aluminum oxide is an uppermost layer of the coating and is the
layer of the coating farthest from the first glass substrate;
wherein the coating is not located between the first and second
glass substrates.
Description
FIELD OF THE INVENTION
Certain example embodiments of this invention relate to articles
including anticondensation coatings, and/or methods of making the
same. More particularly, certain example embodiments of this
invention relate to articles including anticondensation coatings
that are exposed to an external environment, and/or methods of
making the same. In certain example embodiments, the
anticondensation coatings may be survivable in an outside
environment and also may have a low hemispherical emissivity such
that the glass surface is more likely to retain heat from the
interior area, thereby reducing (and sometimes completely
eliminating) the presence condensation thereon. The articles of
certain example embodiments may be, for example, skylights, vehicle
windows or windshields, IG units, VIG units, refrigerator/freezer
doors, and/or the like.
BACKGROUND AND SUMMARY OF EXAMPLE EMBODIMENTS OF THE INVENTION
Moisture is known to condense on skylights, refrigerator/freezer
doors, vehicle windows, and other glass products. Condensation
buildup on skylights detracts from the aesthetic appeal of the
lite. Similarly, condensation buildup on refrigerator/freezer doors
in supermarkets or the like sometimes makes it difficult for
shoppers to quickly and easily pinpoint the products that they are
looking for. And condensation buildup on automobiles often is an
annoyance in the morning, as a driver oftentimes must scrape frost
or ice and/or actuate the vehicle's defroster and/or windshield
wipers to make it safer to drive. Moisture and fog on the
windshield oftentimes presents a similar annoyance, although they
may also pose potentially more significant safety hazards as a
driver traverses hilly areas, as sudden temperature drops occur,
etc.
Various anticondensation products have been developed over the
years to address these and/or other concerns in a variety of
applications. See, for example, U.S. Pat. Nos. 6,818,309;
6,606,833; 6,144,017; 6,052,965; 4,910,088, the entire contents of
each of which are hereby incorporated herein by reference. As
alluded to above, certain approaches use active heating elements to
reduce the buildup of condensation, for example, as in vehicle
defrosters, actively heated refrigerator/freezer doors, etc. These
active solutions unfortunately take time to work in the vehicle
context and thus address the problem once it has occurred. In the
case of refrigerator/freezer doors, such active solutions may be
expensive and/or energy inefficient.
Some attempts have been made to incorporate a thin-film
anticondensation coating on a window. These attempts generally have
involved pyrolytically depositing a 4000-6000 angstrom thick
fluorine-doped tin oxide (FTO) coating on the exterior surface
(e.g., surface 1) of a window such as, for example, a skylight.
Although pyrolytic deposition techniques are known to present "hard
coatings," the FTO unfortunately scratches fairly easily, changes
color over time, and suffers from other disadvantages.
Thus, it will be appreciated there is a need in the art for
articles including improved thin-film anticondensation coatings,
and/or methods of making, the same.
One aspect of certain example embodiments relates to
anticondensation coatings that are suitable for exposure to an
external environment, and/or methods of making the same. The
external environment in certain example instances may be the
outside and/or the inside of a vehicle or house (as opposed to, for
example, a more protected area between adjacent substrates).
Another aspect of certain example embodiments relates to
anticondensation coatings that have a low sheet resistance and a
low hemispherical emissivity such that the glass surface is more
likely to retain heat from the interior area, thereby reducing (and
sometimes completely eliminating) the presence condensation
thereon.
Still another aspect of certain example embodiments relates to
coated articles having an anticondensation coating formed on an
outer surface and one or more low-E coatings formed on one or more
respective interior surfaces of the article. In certain example
embodiments, the anticondensation coating may be thermally tempered
(e.g., at a temperature of at least 580 degrees C. for at least
about 2 minutes, more preferably at least about 5 minutes) or
annealed (e.g., at a temperature lower than that required for
tempering).
The articles of certain example embodiments may be, for example,
skylights, vehicle windows or windshields, IG units, VIG units,
refrigerator/freezer doors, and/or the like.
Certain example embodiments of this invention relate to a skylight
comprising: first and second substantially parallel, spaced apart
glass substrates; a plurality of spacers arranged to help maintain
the first and second substrates in substantially parallel, spaced
apart relation to one another; an edge seal sealing together the
first and second substrates; and an anticondensation coating
provided on an exterior surface of the first substrate exposed to
an environment external to the skylight, the anticondensation
coating comprising the following layers moving away from the first
substrate: a layer comprising silicon nitride and/or silicon
oxynitride, a layer comprising a transparent conductive oxide
(TCO), a layer comprising silicon nitride, and a layer comprising
at least one of zirconium oxide, zirconium nitride, aluminum oxide,
and aluminum nitride, wherein the anticondensation coating has a
hemispherical emissivity of less than less than 0.23 and a sheet
resistance of less than 30 ohms/square. The TCO may be of or
including ITO or the like in certain example embodiments of this
invention.
Certain example embodiments of this invention relate to a skylight.
First and second substantially parallel, spaced apart glass
substrates are provided. A plurality of spacers are arranged to
help maintain the first and second substrates in substantially
parallel, spaced apart relation to one another. An edge seal helps
seal together the first and second substrates. An anticondensation
coating is provided on an exterior surface of the first substrate
exposed to an environment external to the skylight. The
anticondensation coating comprises the following thin-film layers
deposited in the following order moving away from the first
substrate: a silicon-inclusive barrier layer, a first
silicon-inclusive contact layer, a layer comprising a transparent
conductive oxide (TCO), a second silicon-inclusive contact layer,
and a layer of zirconium oxide. The anticondensation coating has a
hemispherical emissivity of less than less than 0.23 and a sheet
resistance of less than 30 ohms/square.
Certain example embodiments of this invention relate to a coated
article comprising: a coating supported by a substrate, wherein the
coating is an anticondensation coating comprising the following
layers moving away from the first substrate: a layer comprising
silicon nitride and/or silicon oxynitride, a layer comprising a
transparent conductive oxide (TCO), a layer comprising silicon
nitride, and a layer comprising one or more of zirconium oxide,
zirconium nitride, aluminum oxide, and aluminum nitride, wherein
the anticondensation coating is disposed on an exterior surface of
the substrate such that the anticondensation coating is exposed to
an external environment, and the anticondensation coating has a
hemispherical emissivity of less than less than 0.23 and a sheet
resistance of less than 30 ohms/square.
Certain example embodiments of this invention relate to a coated
article comprising a coating supported by a substrate. The coating
is an anticondensation coating comprising the following thin-film
layers deposited in the following order moving away from the first
substrate: a silicon-inclusive barrier layer, a first
silicon-inclusive contact layer, a layer comprising a transparent
conductive oxide (TCO), a second silicon-inclusive contact layer,
and a layer of zirconium oxide. The anticondensation coating is
disposed on an exterior surface of the substrate such that the
anticondensation coating is exposed to an external environment. The
anticondensation coating has a hemispherical emissivity of less
than less than 0.23 and a sheet resistance of less than 30
ohms/square.
According to certain example embodiments, the external environment
is the inside of a house or vehicle. According to certain example
embodiments, the external environment is the outside environment.
According to certain example embodiments, a low-E coating is
provided on the substrate opposite the anticondensation
coating.
In certain example embodiments, the coated article may be built
into a skylight, window, insulating glass (IG) window, vacuum
insulating glass (VIG) window, refrigerator/freezer door, and/or
vehicle window or windshield. The anticondensation coating may be
provided on surface one and/or surface four of an IG or VIG unit,
for example.
The features, aspects, advantages, and example embodiments
described herein may be combined to realize yet further
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages may be better and more
completely understood by reference to the following detailed
description of exemplary illustrative embodiments in conjunction
with the drawings, of which:
FIG. 1 is a coated article including an anticondensation coating in
accordance with an example embodiment;
FIG. 2 is an insulating glass unit including an anticondensation
coating (e.g., from any embodiment of this invention such as from
the FIG. 1 and/or FIG. 6 embodiment) disposed on an outermost
surface exposed to the exterior atmosphere in accordance with an
example embodiment;
FIG. 3 is an insulating glass unit including an anticondensation
coating (e.g., from any embodiment of this invention such as from
the FIG. 1 and/or FIG. 6 embodiment) disposed on an innermost
surface exposed to the interior environment in accordance with an
example embodiment;
FIG. 4 is an insulating glass unit including anticondensation
coatings (e.g., from any embodiment of this invention such as from
the FIG. 1 and/or FIG. 6 embodiment) disposed on outermost and
innermost surfaces of the insulating glass unit in accordance with
an example embodiment;
FIG. 5 is a graph illustrating the performance of an example
embodiment, a current anticondensation product, and a bare glass
substrate as the temperature, humidity, and dew point change over
an 18 hour time period; and
FIG. 6 is a coated article including an anticondensation coating in
accordance with an example embodiment of this invention.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION
Referring now more particularly to the accompanying drawings in
which like reference numerals indicate like parts in the several
views.
Certain example embodiments of this invention relate to thin-film
anticondensation coatings that are exposed to the environment. Such
coatings have a low hemispherical emissivity in certain example
embodiments, which helps the glass surface retain heat provided
from the interior side. For instance, in skylight and/or other
building window example applications, the glass surface retains
more heat from the interior of the building. In vehicle example
applications, the windshield retains more heat from the interior of
the vehicle. This helps reduce (and sometimes even prevent) the
initial formation of condensation. As alluded to above, such
anticondensation coatings may be provided on a surface (or multiple
surfaces) exposed to the environment in certain example instances.
As such, the anticondensation coatings of certain example
embodiments may be robust so as to be able to survive such
conditions.
FIG. 1 is a coated article including an anticondensation coating in
accordance with an example embodiment. The FIG. 1 example
embodiment includes a glass substrate 1 supporting a multilayer
thin-film anticondensation coating 3. The anticondensation coating
3 has a low hemispherical emissivity. In certain example
embodiments, the hemispherical emissivity is less than 0.25, more
preferably less than 0.23, still more preferably less than 0.2, and
sometimes even less than 1.0-1.5. This is achieved by providing a
thin transparent conductive oxide layer (TCO) 5 such that a
suitably low sheet resistance is achieved. In the FIG. 1 example,
the TCO 5 is indium tin oxide (ITO). A sheet resistance of the
10-30 ohms/square generally will be sufficient to achieve the
desired hemispherical emissivity values. Certain example
embodiments described herein provide a sheet resistance of 13-27
ohms/square, with the example provided below providing a sheet
resistance of 17 ohms/square. In certain example instances, it is
possible to select a TCO 5 such that the sheet resistance drops to
as low as about 5 ohms/square, although this low value is not need
in all embodiments of this invention. FIG. 6 illustrates a coated
article including similar layers, except that in the FIG. 6
embodiment layers 11 and 13 are not present. In the FIG. 6
embodiment, silicon oxynitride inclusive layer 9b may be both a
silicon-inclusive barrier layer and a lower contact layer, and make
be made up of a combination of layers 9b and 11 from the FIG. 1
embodiment. In the FIG. 1 and FIG. 6 embodiments, the overcoat
layer 7 may be of or include zirconium oxide, aluminum oxide,
aluminum nitride, and/or aluminum oxynitride in example embodiments
of this invention. The layers 9a, 9b and 11 of or including silicon
nitride and/or silicon oxynitride may be doped with aluminum (e.g.,
from about 0.5 to 5% Al) in certain example embodiments, as is
known in the art, so that the target can be conductive during
sputtering of the layer.
Referring to FIGS. 1 and 6, the TCO 5 is protected from the
environment by a layer or zirconium oxide 7. A silicon-inclusive
barrier layer 11 may be provided between the TCO 5 and the
substrate 1 also to help protect the TCO 5, e.g., from sodium
migration. In the FIG. 1 example, the silicon-inclusive barrier
layer 11 is silicon nitride, and the silicon nitride barrier layer
11 is provided adjacent to a layer of titanium oxide 13. The
silicon nitride barrier layer 11 and the layer of titanium oxide 13
help with the optics of the overall article. It will be appreciated
that a low/high/low layer stack system also may be used to improve
the optics of the end product in certain example instances. In
certain example embodiments, the silicon nitride barrier layer 11
may be oxided, e.g., so that it is a layer of silicon oxynitride.
In other words, layer 11 may be of or include silicon oxynitride
for example in certain example embodiments. In certain example
embodiments, a barrier layer comprising silicon nitride (e.g.,
Si.sub.3N.sub.4 or other suitable stoichiometry) may replace the
silicon-inclusive barrier layer 11 and the titanium oxide layer 13
in the FIG. 1 example.
Additional silicon-inclusive layers 9a and 9b may sandwich the TCO
5. As shown in the FIG. 1 example, the upper silicon-inclusive
layer 9a is a layer of silicon nitride, whereas the lower
silicon-inclusive layer 9b is a layer of silicon oxynitride. It
will be appreciated that any suitable combination of silicon with
oxygen and/or nitrogen may be used in different embodiments of this
invention.
The following table provides example physical thicknesses and
thickness ranges for the FIG. 1 example embodiment:
TABLE-US-00001 Example Thickness Example Range (nm) Thickness (nm)
ZrOx (7) 2-15 7 SiNx (9a) 10-50 30 ITO (5) 75-175 130 SiOxNy (9b)
10-50 35 TiOx (13) 2-10 3.5 SiNx (11) 10-20 13
The thicknesses for the layers 9b, 5, 9a and 7 for the FIG. 6
embodiment are similar and the above table is also applicable to
those layers. However, in the FIG. 6 embodiment, silicon nitride
and/or silicon oxynitride based layer 9b may be thicker, e.g., from
about 10-200 nm thick, more preferably from about 10-100 nm thick.
As indicated above, other TCOs may be used in place of, or in
addition to, ITO. For instance, certain example embodiments may
incorporate an ITO/Ag/ITO sandwich. Certain example embodiments,
may incorporate zinc oxide, aluminum-doped zinc oxide (AZO), p-type
aluminum oxide, doped or un-doped Ag, FTO, and/or the like. When Ag
is incorporated into the layer stack system as a TCO, layers
comprising Ni and/or Cr may be provided directly adjacent
(contacting) the Ag. In certain example embodiments, each layer in
the layer stack system may be sputter-deposited. In certain example
embodiments, one or more layers may be deposited using a different
technique. For instance, when FTO is incorporated as the TCO 5, it
may be pyrolytically deposited (e.g., using combustion vapor
deposition or CVD).
In certain example embodiments, layer of diamond-like carbon (DLC)
may be provided directly over and contacting the zirconium oxide.
This may help to create a more survivable, hydrophilic-like coating
in certain example instances. Hydrophilic coatings generally
involve a contact angle of less than or equal to 10 degrees.
Sputter-deposited zirconium oxide tends to have a contact angle of
less than about 20 degrees. However, forming DLC on top of the DLC
on top of the zirconium oxide helps with its wettability and
creates a harder layer. When tempered, for example, a zirconium
oxide/DLC layer stack reaches a contact angle of less than or equal
to about 15 degrees. Thus, a survivable, hydrophilic-like coating
may be achieved. It is noted that this layer may be created by
providing a layer of zirconium nitride followed by a layer of DLC
which, upon tempering, will produce a layer of zirconium oxide
followed by a layer of DLC. See, for example, application Ser. No.
12/320,664, which describes a heat treatable coated article
including DLC and/or zirconium in its coating. The entire contents
of this application are hereby incorporated herein by
reference.
In addition or in the alternative, in certain example embodiments,
a thin hydrophilic and/or photocatalytic coating may be provided
over the zirconium oxide. Such a layer may comprise anatase
TiO.sub.2, BiO, BiZr, BiSn, SnO, and/or any other suitable
material. Such a layer also may help with wettability and/or
provide self-cleaning properties to the article.
In certain example embodiments, the zirconium oxide protective
layer 7 may be replaced with aluminum oxide and/or aluminum
oxynitride. Additionally, in certain example embodiments, the layer
7 may be initially deposited in multi-layer form so as to include a
first layer of or including zirconium nitride directly on silicon
nitride inclusive layer 9a, and a second layer of or including
diamond-like carbon (DLC). Then, when heat treatment (e.g., thermal
tempering including at a temperature(s) of at least about 580
degrees C.) is desired, the coated article is heat treated and the
overlying DLC inclusive layer burns off during heat treatment and
the zirconium nitride inclusive layer transforms into zirconium
oxide thereby resulting in a heat treated coated article having a
heat treated layer stack where the layer 7 is of or includes
zirconium oxide (e.g., see FIGS. 1 and 6).
Although not shown in the FIG. 1 or FIG. 6 examples, a silver-based
low-E coating may be provided on the glass substrate opposite the
anticondensation coating 3. For example, the silver-based low-E
coating may be any one of the low-E coatings described in
application Ser. Nos. 12/385,234; 12/385,802; 12/461,792;
12/591,611; and Ser. No. 12/654,594, the entire contents of which
are hereby incorporated herein by reference. Of course, other low-E
coatings commercially available from the assignee of the instant
invention and/or other low-E coatings also may be used in
connection with different embodiments of this invention. When the
coated article is tempered, it may be run through a tempering
furnace "face down." In other words, when the coated article is
tempered, the anticondensation coating may face the rollers.
In certain example embodiments, the visible transmission may be
high when an anticondensation coating is applied. For example, in
certain example embodiments, the visible transmission preferably
will be at least about 50%, more preferably at least about 60%,
still more preferably at least about 65%. In certain example
embodiments, the visible transmission may be 70%, 80%, or even
higher.
The coated article shown in FIG. 1 or FIG. 6 may be incorporated
into a insulating glass (IG) unit. For example, FIG. 2 is an
insulating glass unit including an anticondensation coating
disposed on an outermost surface exposed to the exterior atmosphere
in accordance with an example embodiment. The IG unit in the FIG. 2
example includes first and second substantially parallel spaced
apart glass substrates 1 and 21. These substrates define a space or
gap 22 therebetween. The first and second substrates 1 and 21 are
sealed using an edge seal 23, and a plurality of pillars 25 help
maintain the distance between the first and second substrates 1 and
21. The first substrate 1 supports the anticondensation coating 3.
As will be appreciated from the FIG. 2 example embodiment, the
anticondensation coating 3 is exposed to the exterior environment.
This is a departure from common practices, where low-E coatings
generally are protected from the external environment. The FIG. 2
arrangement becomes possible because of the durability of the
anticondensation coating 3.
Although not shown in FIG. 2, similar to as described above, a
low-E, coating (e.g., a silver-based low-E coating) may be provided
on an interior surface of one of the first and second substrates 1
and 21. In other words, although not shown in FIG. 2, a low-E
coating may be provided on surface 2 or surface 3 of the IG unit
shown in FIG. 2.
When the FIG. 2 example embodiment is provided in connection with a
skylight application, for example, the outer substrate 1 may be
tempered and the inner substrate 21 may be laminated, e.g., for
safety purposes. This may be true of other IG unit products, as
well, depending on the desired application. In addition, it will be
appreciated that the IG unit structure shown in the FIG. 2 example
may be used in connection with generally vertical and generally
horizontal applications. In other words, the IG unit structure
shown in the FIG. 2 example may be used in refrigerator/freezer
doors that are either generally upright or generally
horizontal.
In certain example embodiments, the space or gap 22 between the
first and second substrates 1 and 21 may be evacuated and/or filed
with an inert gas (such as argon, for example), and the edge seal
23 may provide an hermetic seal, e.g., in forming a vacuum
insulated glass (VIG) unit.
FIG. 2 shows an IG unit having two glass substrates. However, the
example anticondensation coatings described herein may be used in
connection with products that contain first, second, and third
substantially parallel and spaced apart glass substrates (also
sometimes referred to as "triple-glaze" products). The
anticondensation coating may be disposed on surface 1 (the
outermost surface exposed to the environment), and low-E coatings
may be disposed on one or more interior surfaces (surfaces other
than surface 1 and surface 6). For example, the anticondensation
coating may be disposed on surface 1, and low-E coatings may be
disposed on surfaces 2 and 5, 3 and 5, etc., in different
embodiments of this invention. Such triple-glaze products may be IG
units containing three lites or substrates, trip VIG units
containing three lites or substrates, etc., in different
embodiments of this invention.
As indicated above, certain example embodiments may be used in
connection with vehicle windshields, windows, mirrors, and/or the
like. The hemispherical emissivity of the exterior glass surfaces
of a vehicle typically is greater than about 0.84. However, by
reducing the hemispherical emissivity to the above-identified
(and/or other) ranges, the glass surface may retain more heat
provided by the interior of the vehicle. This, in turn, may result
in reduced or eliminated condensation buildup on the lite surface
when a moving vehicle goes from colder to warmer climate (e.g., in
hilly areas), reduced or eliminated condensation and/or frost
buildup on the lite when parked and left over night, etc. The
anticondensation coating in vehicle applications may be provided on
the side of the glass that is exterior to the vehicle cabin.
The zirconium oxide topcoat is advantageous for vehicle window
applications, as it has a comparatively low coefficient of
friction. More particularly, this lower coefficient of friction
facilitates the upward and downward movement of windows.
Certain example embodiments may be used in connection with any
suitable vehicle including, for example, automobiles; trucks;
trains; boats, ships and other vessels; airplanes; tractors and
other work equipment; etc. In vehicle mirror applications, the
optics of the coating may be tune such that a "double reflection"
does not occur.
The inventors of the instant application have also realized that
the anticondensation coating of certain example embodiments may be
used to help meet the so-called "0.30/0.30 standard." Briefly, the
0.30/0.30 standard refers to a U-value of less than or equal to
0.30 and a solar heat gain coefficient (SHGC) of less than or equal
to 0.30. Current legislation in the U.S. would give a tax credit
for investing in windows, skylights, doors, etc., that meet these
criteria.
FIG. 3 is an insulating glass unit including an anticondensation
coating (e.g., see the coating of FIG. 1 and/or FIG. 6) disposed on
an innermost surface exposed to the interior environment in
accordance with an example embodiment. The FIG. 3 example
embodiment is similar to the FIG. 2 example embodiment, except that
the FIG. 3 example embodiment has the anticondensation coating 3
located on surface 4, which is the exterior surface of the inner
glass substrate 1 that is exposed to the building interior rather
than the outside environment.
In certain example embodiments, the inner substrate 1 may be
annealed (rather than tempered). The anticondensation coating may
remain the same or substantially the same as between the FIG. 2 and
FIG. 3 example embodiments, although the modifications described
above in connection with FIGS. 1, 2 and/or 6 also may be made in
connection with an embodiment like FIG. 3. One change that might be
made is increasing the thickness of the ITO to achieve the desired
U-value performance. In such cases where the ITO is thickened, the
thicknesses of the other layers may also be adjusted so that the
desired optical properties are achieved. Additional layers also may
be added to achieve the desired optical properties. The other
structural elements remain the same as between FIGS. 2 and 3, and
similar modifications may be made thereto.
When the anticondensation coating 3 is disposed on surface 4 as
shown in FIG. 3, the U-value has been determined to be 0.29. When
an additional low-E coating is provided on surface 2 of the IG
unit, the U-value has been found to drop to 0.23. Certain example
embodiments also may provide a SHGC less than or equal to 0.30,
thereby helping meet the 0.30/0.30 standard.
In products with low U-values (e.g., IG or VIG units with the
anticondensation coating on surface 4, two- and three-lite VIG
units, etc.), condensation can become a problem, e.g., as the glass
is not heated because of the low-emissivity coatings. One solution
to this challenge is presented in FIG. 4, which is an insulating
glass unit including anticondensation coatings disposed on
outermost and innermost surfaces of the insulating glass unit in
accordance with an example embodiment. In the FIG. 4 example, first
and second substrates 1a and 1b are provided. First and second
anticondensation coatings 3a and 3b are provided on surfaces 1 and
4, respectively. In certain example embodiments, additional low-E
coatings also may be provided on one or both of the inner surfaces
(surfaces 2 and/or 3). In this way, it is possible to provide a
product that exhibits U-value reduction and anticondensation
behaviors.
FIG. 5 is a graph illustrating the performance of an example
embodiment, a current anticondensation product, and a bare glass
substrate as the temperature, humidity, and dew point change over
an 18 hour time period. The images in FIG. 5 each have a
"crisscross" pattern printed thereon to help demonstrate the
presence or absence of condensation. As can be seen from FIG. 5,
there is virtually no condensation formed on those samples that
were produced in accordance with an example embodiment. By
contrast, the comparative example, which includes pyrolytically
deposited FTO, shows some condensation being formed in the first
observed period, with the level of condensation greatly increasing
through the second and third observed periods, and abating slightly
by the fourth observed period. Indeed, the "crisscross" pattern is
significantly blurry at the second observed period and barely
visible during the third. The uncoated glass sample shows
significant condensation during all observed periods. The
"crisscross" pattern in the second and third observed periods
cannot be seen. The FIG. 5 example thus demonstrates that the
example embodiments described herein provide superior performance
when compared to the current comparative example and uncoated
glass.
"Peripheral" and "edge" seals herein do not mean that the seals are
located at the absolute periphery or edge of the unit, but instead
mean that the seal is at least partially located at or near (e.g.,
within about two inches) an edge of at least one substrate of the
unit. Likewise, "edge" as used herein is not limited to the
absolute edge of a glass substrate but also may include an area at
or near (e.g., within about two inches) of an absolute edge of the
substrate(s).
As used herein, the terms "on," "supported by," and the like should
not be interpreted to mean that two elements are directly adjacent
to one another unless explicitly stated. In other words, a first
layer may be said to be "on" or "supported by" a second layer, even
if there are one or more layers therebetween.
While the invention has been described in connection with what is
presently considered to be the most practical and preferred
embodiment, it is to be understood that the invention is not to be
limited to the disclosed embodiment, but on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims.
* * * * *